Patent GB-675124-A (GB)
Title: Time announcing system
IPC: G01D15/24
Filed: 1950-01-19
Abstract: 675,124. Automatic exchange systems. AUTOMATIC ELECTRIC LABORATORIES, Inc. Jan. 19, 1950 [Jan. 28, 1949], No. 1466/50. Class 40 (iv). [Also in Group XXXVIII] An apparatus for giving telephone subscribers time signals and verbal announcements comprises a clock mechanism which gives a tone signal every 15 seconds and a magnetic sound record 210 which is driven intermittently under the control of the clock. The record comprises a film 210 carrying one control track 507, Fig 5, and six parallel sound tracks 501. Each sound track contains announcements for a two-hour period, the film being reversed and the pick-up head being displaced from one track to the next at the end of each period. The verbal announcements include advertisements and time announcement preceding the signals. The seven tracks may be formed on separate wires. An alarm is given if the A.C. power supply fails. Clock mechanism and time signals. The clock is driven by a synchronous motor 100. Six cams 110 are rotated once every twelve hours, cam 111 once an hour, cam 112 once a minute and cams 113 to 115 once every fifteen seconds. Once a revolution, cam 114 grounds oscillator 191 which transmits a tone signal over contacts 192 to a calling line. Verbal announcements are transmitted to the line by an amplifier 190. Record driving and pick-up control mechanism. The sound film 210 is carried by reels 200, 201 and is driven by means of a motor 212 and a capstan 209. The pick-up head 240 is carried by a shaft 236, Fig. 3, and is displaced from one track to the next by means of pins 222 arranged in a spiral on a cam 220. The pins engage a cam follower 228 mounted on the shaft 236. At the end of a twelve-hour period, a spring 305 resets the head in the first track. The control pick-up 211 feeds on amplifier 288 and a rectifier 289 and controls a relay 296 which operates and stops the filmdriving motor 212 when a control signal is reached after each time announcement. General operation. To start the apparatus, contact 293 is momentarily closed to operate relay 290 which locks and provides a ground at 291. Battery for the relays is provided by a rectifier 287 and failure of the power supply allows 290 to relapse and to give an alarm at 295. Relays 180 are operated cyclically for two hours each. When a relay 180 operates, relay 250 starts a motor 241 which drives the cam 220 and the pick-up until one of the six cams 235 corresponding to the operated relay 180 opens the circuit of 250. The pick-up head 240 is then in alignment with the correct sound track 507. Six seconds elapse before cam 113 operates relay 280 which is followed by 258 to start the film driving motor 212. An announcement is made and the motor is stopped by a control signal as described. Relay 270 operates with odd relays 180, and 255 with even relays 180. Relay 260 operates and relapses with 255 to reverse the motor at the beginning of each track. Cam 115 opens the subscriber's line for the period during which the motors are starting and stopping. Advertisements. A second apparatus is used to transmit advertisements during the first six seconds of each fifteen second period. When the cam 114 grounds the oscillator 191, it also operates relay 275 which starts the motor 195 of the second apparatus. At the end of six seconds, the control track operates relay 198 and stops the motor as in the main apparatus.